Molecular And Cellular Biology

Question 1

If the atomic number of an atom is 6, then how many protons does the atom carry? How many electrons?

A) 0 protons and 6 electrons
B) 3 protons and 3 electrons
C) 6 protons and 0 electrons
D) 6 protons and 6 electrons

Answer 1

D) 6 protons and 6 electrons

Atoms are electrically neutral; therefore, the number of protons in an atom equals the number of electrons

Question 2

The mass number of an atom is 23, and its atomic number is 11. How many protons, electrons, and neutrons does this atom carry?

A) 11 protons, 11 electrons , and 12 neutrons

B) 11 protons, 11 electrons, and 1 neutron

C) 11 protons, 1 electron, and 11 neutrons

D) 6 protons, 5 electrons, and 12 neutrons

Answer 2

A) 11 protons, 11 electrons , and 12 neutrons

The number of protons in the nucleus of an atom equals the atomic number. The number of protons and neutrons in the nucleus of an atom equals the mass number. And the number of electrons in an atom are equal because atoms are electrically neutral